This invention relates to mass mailing equipment and concerns Postal requirements to segregate bulk rate mail into zip code areas for delivery to a Post Office.
It has been the practice of mass mailers to station individuals at final discharge conveyors to manually segregate the mail into zip code areas prior to placing the mail into Postal mail bags.
There have been some efforts made to segregate mail by zip code areas mechanically as disclosed by U.S. Pat. Nos. 3,915,785, 3,557,949, and 3,520,404. The known methods entail marking address labels in such a way that zip code change marks can be detected by detection devices which read the marks on the address labels. In at least one system, at a change in marks a detection device sends a signal to a solenoid which shifts an envelope stopping abutment at a laterally moving conveyor adjacent to an exit end of a discharge conveyor. This causes an offset alignment on the lateral conveyor of the mail articles with different zip-code markings. In addition, these devices require counting, or timing, from the time that a change in marks is detected until the solenoid is activated in order to provide for an intervening article movement between the detection device and the stopping abutment. In this respect, a problem with the prior art is that an undue cost for maintaining the critical accuracy needed for timing, or counting, the delay is required.
Another problem in the prior-art abutment system results from the abruptness with which the articles are thereby stopped. In this respect, the articles are shot onto the laterally moving conveyor where their forward motion is stopped abruptly by the shiftable stopping abutment. This sudden stopping frequently causes the mail articles to bounce back or fall askew on the right angle, or laterally moving, conveyor as they change direction.
It is an object of the present invention to eliminate the need for a time, or count, delay from the point of detection to a shiftable stopping abutment.
It is a further objective of this invention to gradually stop the forward movement of mail articles and transfer their movement in a lateral direction smoothly without bouncing or causing them to fall askew on a right angle, or lateral, conveyor so that they are transported laterally, but in easily distinguishable lines that are completely offset for each group having the same unique marking.
It is a further object of this invention to provide such a device which is relatively uncomplicated and relatively inexpensive to manufacture.